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Press Controls--What's New?

One word probably used more than any other in discussions involving pressroom issues these days is ‘flexibility.’ The metalformer must be flexible, able to adapt quickly to changing markets and customer demands. Stamping equipment must be flexible, able to churn out whatever metalformers, with their flexible outlooks, send to the pressroom. Press controls are no different. They, too, must be flexible, providing equipment and process control and information for whatever job comes along.

Such flexibility and the efficiency it can bring—at a price point metalformers can meet—has been driving controls technology development in recent years.

Efficiency Through Increased Automation

“In these downsizing times, metalformers are looking for efficiency, and we are achieving that through automation of control systems,” explains Mary Tice, vice president for press automation at Helm Instrument Co., Inc., Maumee, OH. “With PLC-based control packages, we can integrate all of the press-line components into one common operator interface.”

The advent of PLCs has allowed for greatly simplified control-system expansion, with modules added wherever along the press line that data gathering is required. How simple has it become?

Installing junction boxes on equipment and running interconnect cables back to the control package can accomplish the task, made easier as wiring modules and cables are embedded into the control package, according to Tice.

That has eased control setup and integration, allowing controls manufacturers to develop technology that reaches further into the metalforming process. For example, notes Tice, Helm offers controls “that provide part-gauging SPC right at the machine. We call it on-demand SPC because users can set a time interval for gauging or just have it performed on demand. This allows metalformers to receive that information during the metalforming process instead of after a lot of bad parts are made. Should a part fall out of spec, a list of reasons why, preprogrammed into the system, are communicated, and management can be alerted via pager, e-mail or cell phone.”

Cleaner, Simpler Connection

Advances in serial communication, which requires less wiring than parallel setups, has enabled quick controls installation and expandability.

“We’ve chosen to distribute control and monitoring devices along a high-speed serial bus,” explains Tom Mascari, vice president of engineering for Link Electric & Safety Control, Nashville, TN. “Devices such

This automatic-setups module can adjust shut height, counterbalance and as many as seven cushions.

as programmable limit switches, tonnage monitors, digital and analog die-protection units, automatic shut-height controls, and automatic air systems adjust can be connected to the bus, which connects to an operator terminal for interface with all devices on the bus.”

As each device has its own intelligence capability, the control package can be expanded simply by adding devices to the bus as needed, and the devices themselves allow for further expansion. For example, “Link supplies digital die-protection units with eight or 16 inputs, and as many as five of these units can be added to the bus,” says Mascari, detailinghow technology improvements have expanded control capability. “When fully populated with 16 input units, the system can monitor 80 digital die-protection inputs, and the control package can supply PLC-switch outputs from eight to 96 in groups of eight.”

With the increase in controls capacity comes an equally impressive increase in capability. Mascari recounts a few that Link has implemented.

“The automatic-setups module can automatically adjust shut height, counterbalance and as many as seven cushions,” he says. “The analog die-protection module can perform in-die measurements and drive servo motors to make in die adjustments.”

In a nutshell, control manufacturers have in recent years developed smarts into their packages. One such illustration comes from Link. Should conditions indicate presence of a bad or missing part in one station of a transfer or progressive die, the bad or missing part can be tracked as it progresses through the die. This allows for methods to adapt to a missing part—for example, ignoring sensors in missing-part locations—or ejection of a bad part at a later station in the die.

Work on Any-Sized Press, New or Used

Controls-technology improvements, besides improving flexibility and expandability in press lines, have enabled simplified implementation on presses and lines of varying sizes. The ability to provide a flexible controls solution across new or used, and small, medium and large presses was the driver for Toledo Integrated Systems, Holland, OH, in introducing its Press Pilot 150 press clutch-brake control.

“End users as well as OEMs and rebuilders have numerous applications and requirements for new machines as well as the need to retrofit outdated controls and provide communication with a variety of design platforms,” explains Dan Falcone, sales and marketing manager for Toledo Integrated Systems. “So we developed the Press Pilot 150 to be configured for use

The ability to provide a flexible controls solution across new or used; and small, medium and large presses has driven controls development.

with a resolver, encoder or cams. Further, it can be used as a stand-alone system or integrated with a PLC and other devices via Ethernet or discrete I/O for seamless integration.”

Another new feature, an adjustable clutch-engagement time, accounts for the fact that “some presses kick in slow while others engage very quickly,” says Falcone, “so it is important to have this flexibility.”

Simple applications for this control includes replacing outdated clutch brake controls in single-stroke hand-fed presses, while more demanding applications include interfacing with input (die protection) and output (programmable limit switch) devices as well as continuous on-demand or auto-single-stroke modes of operation. Custom or hybrid applications would include interfacing the press control with a PLC system, ideal for transfer presses, press lines, tandem lines and blanking operations that feature demanding tooling and automation.

Do More with Data

Of course, with press controls, acquiring the data is only half the battle. What can you do with it? That is where Wintriss Controls Group of Honeywell, Acton, MA, has been focusing. Here’s a glimpse into the reporting capabilities now available for press controls, which speaks to the advancements made in data projection.

Wintriss developed reporting to take advantage of its SmartPAC 2 press controllers, which provide timing signals to the presses and ancillary equipment as well as monitor tonnage and die-protection and in-die-measurement sensors. Each controller has a built-in Ethernet port for simple networking.

The company has developed and expanded LETS (Line Efficiency Track Software), which collects production information directly from the SmartPACs and sends it over the existing inhouse Ethernet to the LETS database. The information then is available in report form, or can be accessed using Factory Viewer, a built-in browser-based real-time interface. LETS also can collect from non-Wintriss-equipped equipment.

A LETS datalogger collects data from each control and places it into the database, courtesy of FactoryTalk Transaction Manager, an industry-standard data logger/transaction manager from Rockwell Automation, Milwaukee, WI, that can communicate from various standard and proprietary controls. The database stores production information and feeds the LETS Analyzer, the Report Server, and the Factory Viewer.

The analyzer allows report configuration by date range, shift, machine, tool/part and/or operator. For example, users can specify a report showing production data for four presses producing 10 specific parts, and being run by five selected operators on third shift. Once configured, settings can be saved as a new report. Since it runs on a server, several users can configure reports simultaneously. Reports can be sent to a printer, sent via e-mail to any recipients that you chose, or posted on a network that can be viewed in a web browser by anyone with appropriate access.

The LETS Factory Viewer allows users to glance the status of the entire factory via web browsers. An overview screen shows the status of each machine as well as the parts count, current tool, and estimated time until job completion. Clicking on the machine name accesses detailed job and downtime information. The viewer also lists tools and their status. MF